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  • C01B32/00—Carbon; Compounds thereof
  • C01B32/30—Active carbon
  • C01B32/354—After-treatment
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
  • B01J20/20—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising free carbon; comprising carbon obtained by carbonising processes
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  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D15/00—Separating processes involving the treatment of liquids with solid sorbents; Apparatus therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
  • B01J20/28054—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their surface properties or porosity
  • B01J20/28069—Pore volume, e.g. total pore volume, mesopore volume, micropore volume
  • B01J20/28076—Pore volume, e.g. total pore volume, mesopore volume, micropore volume being more than 1.0 ml/g
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
  • B01J20/28054—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their surface properties or porosity
  • B01J20/28078—Pore diameter
  • B01J20/28085—Pore diameter being more than 50 nm, i.e. macropores
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/3078—Thermal treatment, e.g. calcining or pyrolizing
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  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B32/00—Carbon; Compounds thereof
  • C01B32/30—Active carbon
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  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B32/00—Carbon; Compounds thereof
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  • C01B32/312—Preparation
  • C01B32/318—Preparation characterised by the starting materials
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  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B32/00—Carbon; Compounds thereof
  • C01B32/30—Active carbon
  • C01B32/312—Preparation
  • C01B32/336—Preparation characterised by gaseous activating agents
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B32/00—Carbon; Compounds thereof
  • C01B32/30—Active carbon
  • C01B32/312—Preparation
  • C01B32/342—Preparation characterised by non-gaseous activating agents
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B32/00—Carbon; Compounds thereof
  • C01B32/30—Active carbon
  • C01B32/312—Preparation
  • C01B32/342—Preparation characterised by non-gaseous activating agents
  • C01B32/348—Metallic compounds
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/28—Treatment of water, waste water, or sewage by sorption
  • C02F1/283—Treatment of water, waste water, or sewage by sorption using coal, charred products, or inorganic mixtures containing them
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2006/00—Physical properties of inorganic compounds
  • C01P2006/14—Pore volume
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2006/00—Physical properties of inorganic compounds
  • C01P2006/16—Pore diameter
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2006/00—Physical properties of inorganic compounds
  • C01P2006/22—Rheological behaviour as dispersion, e.g. viscosity, sedimentation stability
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2006/00—Physical properties of inorganic compounds
  • C01P2006/90—Other properties not specified above
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2101/00—Nature of the contaminant
  • C02F2101/30—Organic compounds
  • C02F2101/308—Dyes; Colorants; Fluorescent agents

Definitions

• the present invention relates to activated carbon and a method for producing the same.
• Activated carbon has excellent adsorption capacity and is widely used in liquid phase processing such as removal of impurities in the liquid phase or concentration adjustment of dissolved components.
• the adsorption capacity of activated carbon in liquid phase processing depends largely on whether the properties of the activated carbon itself, such as pore volume and pore distribution, are compatible with the properties of the adsorbate in question.
• Patent Document 1 discloses a decolorizing activated carbon in which the pores in the macropore region of 200 to 1000 nm and 600 to 1000 nm are developed, and this activated carbon is obtained by mixing and grinding two types of coal-based carbonaceous materials. It is disclosed that the mixed powder obtained is manufactured by pressure molding, crushing, heat treatment and activation.
• Patent Document 2 discloses a water treatment or medical adsorbent having a pore volume of 0.02 to 10 ⁇ m adjusted, and the adsorbent is made of a phenol resin as a raw material under specific temperature conditions. It is disclosed to be carbonized and activated.
• the present invention has been made in view of the above circumstances, and it is an object of the present invention to provide activated carbon having high decolorization performance in liquid phase, particularly in liquid phase having relatively high viscosity such as sugar liquid, and a method for producing the same. Do.
• the present invention includes the following preferred embodiments.
• the pore volume at a pore diameter of 10 to 10000 nm by mercury porosimetry is 0.8 to 1.9 mL / g, and the pore volume at a pore diameter of 300 to 1000 nm by mercury porosimetry is 0.
• Activated carbon which is 19 mL / g or more.
• the viscosity measured at a temperature during liquid phase processing using the liquid phase DV-I + VISCOMETER (spindle LV-1, rotational speed 20 rpm) manufactured by BROOKFIELD is 1 to 50 mPa ⁇ s, [3] Or activated carbon as described in [4].
• activated carbon having high decolorization performance in a liquid phase, particularly in a liquid phase having a relatively high viscosity such as a sugar liquid, and a method for producing the same.
• the activated carbon of the present invention has a pore volume of 0.8 to 1.9 mL / g at a pore diameter of 10 to 10000 nm by mercury porosimetry, and a pore volume at a pore diameter of 300 to 1000 nm by mercury porosimetry Is 0.19 mL / g or more.
• Pores with a pore diameter of 10 to 10000 nm not only serve as adsorption sites, but also serve as transport paths for substances to smaller pores. Therefore, if the pore volume at a pore diameter of 10 to 10000 nm is less than 0.8 mL / g, the migration of the adsorbed substance to the inside of the activated carbon is hindered, and the desired adsorption performance (eg, decolorization performance, equilibrium adsorption amount or It is impossible to obtain the decolorization equilibrium achievement rate).
• the desired adsorption performance eg, decolorization performance, equilibrium adsorption amount or It is impossible to obtain the decolorization equilibrium achievement rate.
• the pore volume of the activated carbon of the present invention at a pore diameter of 10 to 10000 nm by mercury porosimetry is preferably 0.9 to 1.7 mL / g, more preferably 1.0 to 1.6 mL / g. And particularly preferably 1.3 to 1.5 mL / g.
• desired adsorption performance is easily obtained, and desired hardness is also easily obtained.
• Pores with a pore diameter of 300 to 1000 nm serve as adsorption sites. In addition, if the pore volume at this pore diameter is large, the diffusion of the adsorbed substance is facilitated. Therefore, when the pore volume at a pore diameter of 300 to 1000 nm is less than 0.19 mL / g, it is not possible to obtain the desired decolorization performance (in particular, the sugar solution decolorization performance and the decolorization equilibrium achievement rate).
• the upper limit of the pore volume at a pore diameter of 300 to 1000 nm is not particularly limited, it is 0 because there is a concern about a decrease in adsorption performance due to a reduction in packing density and a decrease in hardness (JIS hardness and MS hardness, particularly MS hardness). .40 mL / g or less is preferable, 0.38 mL / g or less is more preferable, and 0.37 mL / g or less is more preferable.
• the pore volume of the activated carbon of the present invention at a pore diameter of 300 to 1000 nm by mercury porosimetry is preferably 0.20 mL / g or more, more preferably 0.23 mL / g or more, and still more preferably 0. It is at least 25 mL / g, particularly preferably at least 0.30 mL / g. If the pore volume is within the above range, activated carbon having desired adsorption performance and hardness can be easily obtained.
• the specific pore volume at the specific pore diameter as described above is such that the potassium element content of the raw material activated carbon is 0.5% by mass or less and the calcium element content is 0.4 to 4 mass, as described later. It can adjust by giving activation after adjusting to%.
• the activation yield should be selected appropriately to obtain a specific pore volume at such a specific pore diameter.
• the hardness (hereinafter also referred to as "JIS hardness") of the activated carbon of the present invention measured according to JIS K 1474 is preferably 70% or more, and more preferably 72% or more.
• JIS hardness preferably 70% or more, and more preferably 72% or more.
• the micro strength hardness (hereinafter also referred to as “MS hardness”) of the activated carbon of the present invention is preferably 45% or more, more preferably 50% or more.
• the MS hardness is an indicator of resistance to weight loading and is measured by the method described in the examples below.
• the specific hardness as described above, as described later, is adjusted after adjusting the potassium element content of the raw material activated carbon to 0.5 mass% or less and the calcium element content to 0.4 to 4 mass%. It can adjust by adjusting a rate suitably and giving activation. If the pore volume at a pore diameter of 10 to 10000 nm, and particularly the pore volume at a pore diameter of 300 to 1000 nm, is too large, the hardness (JIS hardness and MS hardness, particularly MS hardness) tends to decrease. Adjustment of pore volume at a specific pore diameter is important for achieving both hardness and adsorption performance.
• the activated carbon of the present invention is suitable for use in liquid phase processing because it has a specific pore volume at a specific pore diameter. Therefore, in one aspect of the present invention, the activated carbon of the present invention is a liquid phase processing activated carbon.
• the activated carbon of the present invention having high MS hardness is useful for liquid phase processing using an adsorption column, an adsorption column or the like.
• the liquid phase may be one which exists as a liquid phase under normal processing conditions. Examples of liquid phases include solutions, dispersions, emulsions, microemulsions, suspensions, oils and alcohols.
• the liquid phase treatment include a treatment for removing impurities in the liquid phase, and a treatment for adjusting the concentration of the dissolved component.
• the liquid phase treatment is treatment for removing colored components from the liquid phase (decolorization treatment).
• the activated carbon of the present invention can also be used to treat liquid phases having a relatively high viscosity. Therefore, in one aspect of the present invention, the viscosity measured at the time of liquid phase processing using liquid phase BROOKFIELD DV-I + VISCOMETER (spindle LV-1, rotational speed 20 rpm) is 1 to 50 mPa ⁇ s. .
• the liquid phase having such viscosity include, but are not limited to, sugar solution, tung oil and glycerin.
• the temperature at the time of liquid phase treatment differs depending on the target liquid phase.
• the liquid phase is a sugar liquid, it is about 40 to 60 ° C., for soy sauce, it is about 15 to 35 ° C., and for glycerin, it is about 70 ° C.
• the dye adsorption amount of activated carbon for example, an SPR aqueous solution in the evaluation using the dye Solophenyl RED 3BL (hereinafter referred to as "SPR") described later] Is the normal temperature (25 ° C.).
• the decolorization performance of the activated carbon of the present invention can be evaluated, for example, using a sugar solution or soy sauce in the method described in the following examples.
• the sugar solution decolorization performance is particularly preferably 40% or more, more preferably more than 50%.
• the soy sauce decolorization performance is more preferably 80% or more, particularly preferably more than 90%.
• the dye adsorption amount of the activated carbon of the present invention can be evaluated, for example, by determining the equilibrium adsorption amount and the decolorization equilibrium arrival rate using SPR by the method described in the later examples.
• the SPR equilibrium adsorption amount is preferably 90 mg / g or more, more preferably 94 mg / g or more, particularly preferably 98 mg / g or more, and the SPR decolorization equilibrium achievement rate is preferably 50% or more, more preferably 55% or more And particularly preferably 58% or more.
• the above-mentioned equilibrium adsorption amount and decolorization equilibrium achievement rate can be obtained by adjusting the pore volume at a pore diameter of 10 to 10000 nm and the pore volume at a pore diameter of 300 to 1000 nm within a specific range or above the lower limit.
• Be The activated carbon of the present invention is useful in liquid phase processing using an adsorption column, an adsorption column, or the like because it can adsorb and remove impurities such as dyes quickly and efficiently.
• Activated carbon is used for liquid phase treatment, and activated carbon with reduced adsorption performance (decoloring performance) is regenerated by predetermined treatment and reused.
• the activated carbon of the present invention is a step of reducing the potassium element contained in the raw material activated carbon (hereinafter, also referred to as “potassium reduction step”), a step of contacting the raw material activated carbon with a calcium element supply source (hereinafter, “calcium contacting step” Step of activating the raw material activated carbon whose potassium element content and calcium element content have been adjusted (hereinafter also referred to as “secondary activation step”), and a step of acid-cleaning the raw material activated carbon after activation (Also referred to as “acid washing step”)).
• activated carbon refers to the activated carbon obtained through the four steps included in the above-described manufacturing method
• raw activated carbon refers to activating treatment (primary activation treatment) of an activated carbon precursor.
• the present invention shows activated carbon as a raw material of the activated carbon of the present invention, which is not obtained through all the above four steps (that is, including those in the middle of the above manufacturing steps).
• Raw material activated carbon is preferably activated carbon derived from coconut shell. Therefore, in a preferred embodiment of the present invention, the activated carbon of the present invention is made from coconut shell-derived activated carbon. Since the raw material activated carbon is derived from coconut shell, the raw material activated carbon particles have a structure pore unique to coconut shell, so the calcium element supply source is easily diffused inside the particle, and the pore development is promoted in the activation step. It is easy to be done. It is also commercially advantageous as it is available in large quantities.
• the coconut used as the raw material of coconut shell is not specifically limited.
• palm palm oil palm
• coconut palm coconut palm
• the coconut husks obtained from these palms may be used alone or in combination of two or more.
• coconut husks derived from coconut or palm palm which are biomass wastes which are used as food, detergent raw materials, biodiesel raw materials, etc., are particularly preferable because they are easily available and inexpensive. .
• coconut shells in the form of pre-fired char (coconut char), which is preferably used as a raw material.
• char may be produced from coconut shells and used.
• the method for producing the char is not particularly limited, and can be produced using methods known in the art.
• a coconut shell serving as a raw material is mixed with an inert gas such as nitrogen, helium, argon or carbon monoxide, a mixed gas of these inert gases, or a mixture of other gases mainly composed of these inert gases
• a coconut husk char can be produced by firing (carbonization) at a temperature of about 400 to 800 ° C. in a gas atmosphere.
• the raw material activated carbon used in the present invention can be obtained, for example, by subjecting the above-mentioned activated carbon precursor (cow shell char) to activation treatment (primary activation treatment).
• the activation treatment is a treatment to form pores on the surface of the activated carbon precursor and convert it to a porous carbonaceous material, whereby an activated carbon (raw activated carbon) having a large specific surface area and pore volume can be obtained.
• the activated carbon precursor is used as the raw material activated carbon without performing the primary activation treatment, the specific surface area and pore volume of the obtained carbonaceous material are not sufficient, and when used for liquid phase treatment, it is in the liquid phase. It is difficult to obtain sufficient effects in removing impurities or adjusting the concentration of the dissolved component, and therefore it is impossible to obtain the activated carbon of the present invention.
• the primary activation treatment may be carried out in a mixed gas atmosphere of water vapor, nitrogen and carbon dioxide at 800 ° C. or higher, preferably 800 to 1000 ° C., using a fluidized bed, a multistage furnace, a rotary furnace or the like. it can.
• the partial pressure of gas at that time is not particularly limited, but it is preferable that the partial pressure of water vapor is 7.5 to 40%, the partial pressure of carbon dioxide 10 to 50%, and the partial pressure of nitrogen 30 to 80%.
• the total pressure of the gas is usually 1 atm (about 0.1 MPa).
• the total supply amount of the mixed gas at the time of primary activation is about 1 to 50 L / min with respect to 100 g of the activation sample. If the total amount of the activated gas supplied is within the above range, the activated reaction can be more efficiently progressed.
• the specific surface area (hereinafter also referred to as “BET specific surface area”) calculated by the BET method of the raw material activated carbon in the present invention is preferably 900 m 2 / g to 1500 m 2 / g.
• BET specific surface area calculated by the BET method of the raw material activated carbon in the present invention
• the potassium element in the raw material activated carbon is reduced to 0.5% by mass or less. This is because, in the presence of an abundance of elemental potassium, in the secondary activation step after contact with the elemental calcium source, the development of micropore volume is promoted rather than the development of meso to macropore volume suitable for liquid phase treatment In order to Therefore, when the potassium element in the raw activated carbon exceeds 0.5% by mass, it is impossible to obtain a specific pore volume at a specific pore diameter in the activated carbon of the present invention.
• the content of potassium element in the raw material activated carbon is preferably 0.3% by mass or less. A desired pore volume is easy to be obtained as potassium element content is below the said value.
• the content of potassium element is measured by the method described in the examples below.
• the lower limit value of the content of potassium element is 0.0% by mass, which is the detection limit of the measurement method.
• the method for reducing the potassium element is not particularly limited, and examples thereof include washing with a washing solution containing an acid, and exchange of a potassium component and another component (for example, a calcium component) by ion exchange action.
• the calcium element supply source is brought into contact with the raw material activated carbon having a reduced potassium element content in the potassium reduction step.
• an element of calcium source adheres to the surface and pores of the raw activated carbon.
• the content of the calcium element contained in the raw material activated carbon after contact is 0.4 to 4% by mass. If the content of elemental calcium is not within the above range, it is not possible to obtain a specific pore volume at a specific pore diameter in the activated carbon of the present invention even after the subsequent secondary activation step and acid treatment step.
• the content of the calcium element contained in the raw material activated carbon after contact is preferably 0.5 to 3% by mass. When the calcium element content is in the above range, a desired pore volume can be easily obtained.
• the content of the calcium element is measured by the method described in the following examples.
• the calcium element source is not particularly limited, and, for example, a water-insoluble calcium compound or a water-soluble calcium compound can be used.
• the calcium compounds can be used alone or in combination of two or more.
• non-water soluble calcium compounds include calcium carbonate and calcium hydroxide. From the viewpoint of handling safety, it is preferable to use calcium carbonate.
• a water-soluble calcium compound from the viewpoint of being able to contact in the form of an aqueous solution and uniformly attach the calcium element source.
• Specific examples of water soluble calcium compounds include calcium chloride, calcium nitrate and calcium acetate. Among them, calcium nitrate is preferable because it has high solubility, is easily available, and is inexpensive. Moreover, in view of waste liquid treatment and the like, it is preferable to use calcium chloride or calcium acetate from the viewpoint of low environmental load.
• any method may be used as long as the calcium element source can be attached to the raw material activated carbon.
• a method of spraying an aqueous solution of a calcium element supply source on a raw material activated carbon for example, a method of spraying an aqueous solution of a calcium element supply source on a raw material activated carbon, a method of immersing a raw material activated carbon in a solution of a calcium element supply source, and mixing the raw material activated carbon and a powdered calcium element supply source And the like.
• a method of contacting the calcium source with the raw material activated carbon as an aqueous solution such as spraying or dipping, is preferable because it easily adheres the calcium element source uniformly to the surface and pores of the raw material activated carbon.
• the potassium component can be discharged into the aqueous solution by ion-exchanging the potassium component in the raw material activated carbon to the calcium component, so the potassium reduction step and the calcium contact step can be performed simultaneously. It can be carried out.
• the raw material activated carbon after contact with the calcium element supply source is usually dried before the secondary activation step, but after sufficient water is removed, it is left as it is It may be subjected to secondary activation treatment.
• ⁇ Secondary activation process> The raw activated carbon after being subjected to the potassium reduction step and the calcium contact step is subjected to a secondary activation treatment.
• This secondary activation process is the same as the above-mentioned "primary activation process” except that the activation target is calcium-adhered activated carbon.
• ⁇ Acid washing process> By cleaning the raw material activated carbon after the secondary activation step with an acid-containing cleaning solution, impurities such as metal components contained in the raw material activated carbon are removed.
• the acid cleaning can be performed, for example, by immersing the raw material activated carbon after secondary activation in the acid-containing cleaning liquid.
• the acid washing step after the raw activated carbon is acid washed, it may be washed with water, or the acid washing and the water washing may be appropriately combined, such as repeating the acid washing and the water washing.
• the acid component may be blown away by heating.
• inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid, or saturated carboxylic acids such as formic acid, acetic acid, propionic acid, oxalic acid, tartaric acid and citric acid, or aromatic carboxylic acids such as benzoic acid and terephthalic acid
• an organic acid such as an acid.
• hydrochloric acid which does not oxidize the raw material activated carbon.
• the concentration of hydrochloric acid is preferably 0.1 to 10% by mass, and more preferably 0.3 to 6% by mass.
• the concentration of hydrochloric acid is too low, it is necessary to increase the number of times of pickling to remove impurities. Conversely, if it is too high, the amount of residual hydrochloric acid will increase.
• the process can be performed, which is preferable from the viewpoint of productivity.
• the liquid temperature at the time of pickling and washing with water is not particularly limited, but it is preferably 0 to 100 ° C., more preferably 10 to 100 ° C., and still more preferably 15 to 95 ° C. If the temperature of the cleaning solution at the time of immersing the raw material activated carbon is within the above-mentioned range, it is preferable because the implementation of the cleaning can be carried out while suppressing the load on the apparatus for a practical time.
• the activated carbon after the acid washing is dried to obtain the activated carbon of the present invention.
• the drying method is not particularly limited, and any known drying means may be used.
• drying may be performed using a natural convection constant temperature dryer, a forced convection constant temperature dryer, a vibrating flow dryer, or the like.
• the drying temperature is preferably 80 to 150 ° C.
• the loss on drying of the activated carbon after drying is preferably 5% by mass or less.
• the activated carbon of the present invention produced in this manner has high performance in liquid phase processing (impurity removal performance, dissolution component, etc.) due to the development of a specific pore volume including the mesopore to macropore region.
• the decolorization in addition to the liquid phase having a low viscosity, the decolorization can be improved even in a liquid phase having a relatively high viscosity such as a sugar solution, and a balanced decoloring performance can be exhibited.
• the BET specific surface area and metal element content of the raw material activated carbon, and the pore volume of the activated carbon, JIS hardness and MS hardness were determined according to the following methods.
• BELSORP 28SA surface area / pore distribution measuring device
• ⁇ Average particle size> In evaluating the metal element content of the raw material activated carbon and the decolorization performance of the activated carbon, it is necessary to grind the raw material activated carbon or the activated carbon so as to have a predetermined average particle diameter. Therefore, it was measured by the laser diffraction measurement method whether the predetermined
• Microtrack Bell a laser diffraction / scattering particle size distribution measuring device
• Measurement count once Measurement time: 30 seconds
• Distribution display Volume Particle size classification: Standard Calculation mode: MT3000II Solvent name: WATER Upper limit of measurement: 2000 ⁇ m Measurement lower limit: 0.021 ⁇ m Remainder ratio: 0.00 Passage ratio: 0.00 Residual ratio setting: invalid particle permeability: transmission particle refractive index: 1.81 Particle shape: non-spherical Solvent refractive index: 1.333 DV value: 0.0150 to 0.0700 Transmittance (TR): 0.700 to 0.950 In the measurement results, the value of D50 was taken as the average particle size.
• ⁇ Metal element content of raw material activated carbon First, a calibration curve was prepared for the contents of elemental potassium and elemental calcium from a standard solution of known concentration. Next, the raw material activated carbon pulverized to have an average particle diameter of 20 ⁇ m or less was dried at 115 ⁇ 5 ° C. for 3 hours, and then 0.1 g was placed in a predetermined container. After adding 10 mL of nitric acid (60.0 to 62.0% by mass) to this container and mixing, using a microwave sample pretreatment apparatus ("MARS 6" manufactured by CEM Japan Ltd.), 1 at a temperature of 210 ° C. It pretreated for time and decomposed the raw activated carbon.
• MERS 6 microwave sample pretreatment apparatus
• the resulting solution was taken out, ion exchange water was added to 200 mL to prepare a measurement solution, and analysis was performed using a multi-type ICP emission analyzer ("ICPE-9820" manufactured by Shimadzu Corporation).
• ICPE-9820 manufactured by Shimadzu Corporation.
• the concentration of each metal element was determined from the obtained values and the prepared calibration curve, and the contents of the potassium element and the calcium element were determined by the following equation.
• ⁇ Pore volume of activated carbon The pore volume per activated carbon mass was measured using a mercury intrusion pore volume measuring apparatus ("MicroActive AutoPore V 9600" manufactured by Micromeritics, Inc.). The mercury pressure was from 0.10 psia (about 0.69 kPa) to 61000.00 psia (about 420580.19 kPa).
• JIS hardness of activated carbon was measured in accordance with JIS K1474.
• ⁇ MS hardness of activated carbon> Ten 8 mm steel balls were placed in a steel pot having an inner diameter of 25.4 mm and a length of 304.8 mm, and further, about 5.0 g of dried activated carbon (weighed to a digit of 0.1 g) was placed and sealed. The steel pot was attached to a measuring instrument and rotated at a speed of 25 revolutions per minute for 40 minutes. Thereafter, the sample was taken out, the steel balls were removed, and the sample was sieved with a 50 mesh sieve (JIS standard). The ratio (unit:%) of the sample remaining on the sieve to the sample initially placed in the steel pot was calculated according to the following formula, and was defined as MS hardness.
• Example 1 Preparation of Raw Material Activated Carbon Char (a specific surface area: 370 m 2 / g) using coconut shell of Filipino coconut is used as a raw material in a rotary kiln, using propane combustion gas + water vapor (total water vapor partial pressure: 35%) A raw material activated carbon having a specific surface area of 1141 m 2 / g, which was activated at ° C. and sized to a 10 to 30 mesh sieve (JIS standard), was obtained.
• an aqueous solution of calcium nitrate (23 g of calcium nitrate tetrahydrate, 117 g of ion-exchanged water) is sprayed on 500 g of the obtained activated carbon and then dried for 5 to 7 hours in a natural convection constant temperature drier at 115 ⁇ 5 ° C. did.
• the calcium element content of the obtained calcium element-containing activated carbon was 0.8% by mass.
• 450 g of the calcium element-containing activated carbon thus obtained is placed in a fluidized furnace, and a mixed gas of 16% water vapor partial pressure, 12% carbon dioxide partial pressure and 72% nitrogen partial pressure is used.
• Example 2 Activated carbon was obtained in the same manner as in Example 1 except that the activation yield was 33.0%. Physical properties of the obtained activated carbon are shown in Table 1.
• Example 3 Activated carbon was obtained in the same manner as in Example 1 except that the activation yield was 39.5%. Physical properties of the obtained activated carbon are shown in Table 1.
• Example 4 500 g of raw material activated carbon obtained in the same manner as in Example 1 is immersed in an aqueous calcium nitrate solution (55.1 g of calcium nitrate tetrahydrate, 1125 g of ion exchanged water), stirred at room temperature for 6 hours, and filtered at 115 ⁇ 5 ° C. It dried with the natural convection constant temperature dryer for 5 to 7 hours.
• the potassium element content of the obtained calcium element-containing activated carbon was 0.4% by mass, and the calcium element content was 0.9% by mass.
• Activated carbon was obtained in the same manner as in Example 1 except that the activation yield was set to 26.0% with respect to this calcium element-containing activated carbon. Physical properties of the obtained activated carbon are shown in Table 1.
• Example 5 Immersed in an aqueous solution of calcium chloride (26.9 g of calcium chloride, 1125 g of ion exchanged water), 500 g of raw activated carbon obtained in the same manner as in Example 1, stirred at room temperature for 6 hours, and after filtration, natural convection constant temperature of 115 ⁇ 5 ° C. It was dried for 5 to 7 hours in a drier.
• the potassium element content of the obtained calcium element-containing activated carbon was 0.3% by mass, and the calcium element content was 1.1% by mass.
• Activated carbon was obtained in the same manner as in Example 1 except that the activation yield was 33.2% with respect to the calcium element-containing activated carbon. Physical properties of the obtained activated carbon are shown in Table 1.
• Example 6 Activated carbon was obtained in the same manner as in Example 1 except that the activation yield was set to 9.1%. Physical properties of the obtained activated carbon are shown in Table 1.
• Example 7 Activated carbon was obtained in the same manner as in Example 1 except that the activation yield was 45.2%. Physical properties of the obtained activated carbon are shown in Table 1.
• Comparative Example 1 A bituminous coal having a weak caking property with a button index of 1 measured according to the crucible expansion test method of JIS M 8806 6, and a slightly caking bituminous coal with a button index of 0.5 were mixed at a mass ratio of 3: 7. Next, 20 parts by mass of strongly coking coal having a button index of 9 was added to 100 parts by mass of the mixture, and mixed and pulverized using a ball mill. The obtained ground product was filled in a container having a diameter of 4 cm and a length of 15 cm using a pressure molding machine, and pressure molded at 100 ° C. and a pressure of 280 kg / cm 2 .
• the obtained pressure-molded product was crushed with a jaw crusher and sized to a particle size of 0.1 to 2.0 mm.
• This sized product is placed in an external heating rotary kiln, heated to 300 ° C. in an oxidizing gas atmosphere, held for 2 hours, heated to 650 ° C. in a reducing gas atmosphere, and then cooled to obtain a carbonized product. Obtained. 75 g of this carbonized product is placed in a fluidized-bed furnace, and a mixed gas of steam partial pressure 16%, carbon dioxide partial pressure 12%, and nitrogen partial pressure 72% is contained in the furnace at a total pressure of 1 atmosphere and a flow rate of 21.7 L / min. And the activation was carried out at an activation temperature of 950.degree. C. to an activation yield of 50.0%.
• the obtained activated product was subjected to measurement of packing density, acid washing, water washing and drying in the same manner as in Example 1 to obtain activated carbon. Physical properties of the obtained activated carbon are shown in Table 1.
• Comparative example 2 Activated carbon was obtained in the same manner as in Example 1 except that the activation yield was 81.9%. Physical properties of the obtained activated carbon are shown in Table 1.
• Comparative example 3 Activated carbon was obtained in the same manner as in Example 1 except that the activation yield was 59.5%. Physical properties of the obtained activated carbon are shown in Table 1.
• Comparative example 4 Calcium nitrate aqueous solution (23 g of calcium nitrate tetrahydrate, 117 g of ion-exchanged water) is sprayed onto the raw material activated carbon without carrying out the adjustment process of the potassium element content to the raw material activated carbon in Example 1, and natural at 115 ⁇ 5 ° C. It was dried for 5 to 7 hours with a convection constant temperature dryer. The potassium element content of the obtained calcium element-containing activated carbon was 0.7% by mass, and the calcium element content was 0.7% by mass. Activated carbon was obtained in the same manner as in Example 1 except that the activation yield was 80.4%. Physical properties of the obtained activated carbon are shown in Table 1.
• Comparative example 5 Activated carbon was obtained in the same manner as in Comparative Example 4 except that the activation yield was adjusted to 57.0%. Physical properties of the obtained activated carbon are shown in Table 1.
• Comparative example 7 Activated carbon was obtained in the same manner as in Comparative Example 4 except that the activation yield was 30.4%. Physical properties of the obtained activated carbon are shown in Table 1.
• Comparative Example 8 Activated carbon was obtained in the same manner as in Comparative Example 4 except that the activation yield was 18.2%. Physical properties of the obtained activated carbon are shown in Table 1.
• Comparative Example 9 After holding 700 g of a phenol resin in an external heating rotary kiln at 300 ° C. for 2 hours, the temperature was raised to 650 ° C. and then cooled to obtain a carbonized product. 180 g of this carbonized product was placed in a rotary kiln adjusted to a temperature of 900 ° C., and activated with 5 L / min of nitrogen and 180 g / hour of steam for 6 hours. Physical properties of the obtained activated carbon are shown in Table 1.
• this raw sugar aqueous solution is adjusted with a 0.1 mol / L hydrochloric acid or sodium hydroxide aqueous solution so that the pH becomes 6.5 to 7.5, and a sugar content meter ("Pocket sugar content meter PAL-2" manufactured by Atago Co., Ltd.)
• the sugar content was confirmed to be 50.0% using
• the sugar content was adjusted to 50.0% by adding raw sugar or ion-exchanged water, and this was used as a raw sugar solution.
• the value of the measured absorbance is higher than the above-mentioned specified range (when it is higher than 0.78)
• a purified sugar solution is added to adjust to the above-mentioned specified range, and a sugar test solution is prepared.
• the measured absorbance value is lower than the above specified range (if it is lower than 0.75)
• the production lot of raw sugar is changed and preparation is performed again, and the solution whose absorbance falls within the predetermined range is It was a test solution.
• the viscosity at the temperature (50 ° C.) of the liquid phase treatment of the sugar test solution was 7 mPa ⁇ s.
• the powdered activated carbon to be measured was dried at 115 ⁇ 5 ° C.
• the sugar solution decoloring performance was evaluated according to the following criteria. A: Greater than 50% B: 40 to 50% C: 30 to less than 40% D: less than 20 to 30% E: less than 20%
• Soy sauce (“Special soy beans soy sauce” made by Kikkoman Foods Co., Ltd.) was diluted about 10 times with ion-exchanged water to adjust the absorbance at a wavelength of 550 nm to 0.47 to 0.55, and used as a soy sauce test solution. .
• the viscosity at the temperature (25 ° C.) of the liquid phase treatment of the soy sauce test solution was 2 mPa ⁇ s.
• a quartz cell (optical path length 10 mm) was used for absorbance measurement, and an ultraviolet-visible spectrophotometer ("UV-1800" manufactured by Shimadzu Corporation) was used.
• ion-exchanged water was used for zero point correction at the time of absorbance measurement.
• the powdered activated carbon to be measured was dried at 115 ⁇ 5 ° C. for 3 hours and allowed to cool in a desiccator. 0.20 g of powdery activated carbon after cooling was weighed and placed in a 100 mL stoppered Erlenmeyer flask. Add 40 mL of soy sauce test solution to this flask, shake for 15 minutes with an amplitude of 160 times / minute in a water bath adjusted to 25 ⁇ 1 ° C., filter using 5 C filter paper, and discard 5 mL of the first filtrate, The filtrate after that was filtered again to obtain a sample solution.
• the above-mentioned operation was performed without powdered activated carbon, and the obtained filtrate was used as a blank solution.
• the absorbance at a wavelength of 550 nm was measured for each solution, and the soy sauce decolorization performance was calculated by the following equation.
• ion-exchanged water was used for zero point correction at the time of absorbance measurement.
• soy sauce bleaching performance was evaluated according to the following criteria. A: Greater than 90% B: 80-90% C: less than 65 to 80% D: less than 55 to 65% E: less than 55%
• Dye adsorption amount A 0.1 mass% SPR aqueous solution was prepared using SPR and ion exchange water. The viscosity at the temperature (25 ° C.) of the liquid phase processing of the SPR aqueous solution was 2 mPa ⁇ s. Two samples were prepared by adding 20 mL of the above SPR aqueous solution to 0.2 g of activated carbon that was sized with a 10-30 mesh sieve (JIS standard) and prepared, and amplitude 160 times / min in a water bath adjusted to 25 ⁇ 1 ° C. Shake.
• One of the samples was shaken for 90 minutes, and the other sample was shaken for 24 hours, and then filtered with a mini-salt (pore diameter: 0.45 ⁇ m), and the filtrate was used as a measurement sample. Moreover, the above operation was performed without activated carbon, and the obtained filtrate was used as a blank solution.
• the absorbance at a wavelength of 520 nm was measured for each of the measurement samples and the blank solution after 100-fold dilution with ion-exchanged water.
• a quartz cell (optical path length 10 mm) was used for absorbance measurement, and an ultraviolet-visible spectrophotometer ("UV-1800" manufactured by Shimadzu Corporation) was used.
• the dye adsorption amount was determined by the following formula. The SPR adsorption amount at 24 hours was taken as the SPR equilibrium adsorption amount.
• the SPR decolorization equilibrium achievement rate at 90 minutes of shaking time was calculated according to the following formula. The higher the decolorization equilibrium achievement rate, the faster the adsorption rate.
• the SPR equilibrium adsorption amount is also high, and the SPR decolorization equilibrium achievement rate in a short time of 90 minutes is also high. It was shown that the adsorption amount and the adsorption rate of SPR are excellent.
• the SPR equilibrium adsorption amount was significantly lower than that of the example, and the SPR decolorization equilibrium achievement rate was also significantly lower.
• the SPR equilibrium adsorption amount was sufficient, the SPR decolorization equilibrium achievement rate did not reach that of the example, and it was shown that the adsorption rate was slow.
• the activated carbons obtained in Examples 1 to 7 have excellent sugar solution decolorization performance and soy sauce decolorization performance, as well as excellent SPR equilibrium adsorption amount and SPR decolorization equilibrium achievement rate, as well as high JIS hardness of 70% or more and It had a high MS hardness of 45% or more.
• the activated carbon of the present invention is useful as a liquid phase processing application because it has excellent decolorization performance and decolorization equilibrium achievement rate. In addition to low viscosity liquid phase such as soy sauce, it also exhibits high decolorization performance even in liquid phase with relatively high viscosity such as sugar liquid, especially as activated carbon for processing various liquid phases. It can be used suitably.
• the activated carbon of the present invention having high hardness can be suitably used for liquid phase treatment in an adsorption column, an adsorption column or the like where such characteristics are required.
• the activated carbon of the present invention can be manufactured by a simple method of changing the balance between the amounts of two metal elements in the manufacturing process and activating the same, which is also industrially useful in this respect.

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